of: include errno.h
of: include errno.h

When compiling ath6kl for beagleboard (omap2plus_defconfig plus
CONFIG_ATH6KL, CONFIG_OF disable) with current linux-next compilation
fails:

include/linux/of.h:269: error: 'ENOSYS' undeclared (first use in this function)
include/linux/of.h:276: error: 'ENOSYS' undeclared (first use in this function)
include/linux/of.h:289: error: 'ENOSYS' undeclared (first use in this function)

Fix this by including errno.h from of.h.

Signed-off-by: Kalle Valo <7081a7d99b8c74c0698a728df19e3915a995d7e1@qca.qualcomm.com>
Acked-by: Geert Uytterhoeven <0da414d9d963da4039c2a0525b1844228075aa58@linux-m68k.org>
Signed-off-by: Grant Likely <9069e6f5a2b566e2674a0ba1e2bf39c12c195fad@secretlab.ca>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas